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不同雷诺数下螺旋槽径向气体轴承承载特性分析

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润滑与密封 2024年第6期49卷 91-97页

作者：张鑫殷玉枫唐杰太原科技大学机械工程学院山西太原030024

为研究螺旋槽径向气体轴承在不同雷诺数下承载力的变化规律,建立基于Ng-Pan理论修正的气体轴承润滑模型,利用有限差分法求解该模型,得到不同雷诺数下轴承的承载特性,分析轴承几何参数和槽型参数的变化对承载力的影响。结果表明:螺旋槽... 详细信息

为研究螺旋槽径向气体轴承在不同雷诺数下承载力的变化规律,建立基于Ng-Pan理论修正的气体轴承润滑模型,利用有限差分法求解该模型,得到不同雷诺数下轴承的承载特性,分析轴承几何参数和槽型参数的变化对承载力的影响。结果表明:螺旋槽径向气体轴承在非层流润滑状态下承载力大于层流润滑状态下的承载力;轴承几何参数对承载特性影响显著,其中随偏心率增大承载力呈发散式增大,且非层流状态下承载力与层流状态下承载力差距加大,随长径比增大承载力呈收敛式增加;轴承槽型参数中槽宽比、槽深比对承载特性有明显影响,随槽宽比、槽深比增加轴承承载力增加,而槽数对轴承承载力的影响并不显著,螺旋角对非层流状态下轴承承载力影响较大;轴承进口压力对承载性能有明显影响,随进口压力增大,承载力在层流状态下增加,在非层流状态下波动较大。

关键词：螺旋槽径向气体轴承 Ng-Pan理论承载特性雷诺数层流润滑状态

径向螺旋槽空气轴承起飞速度与承载能力试验研究

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润滑与密封 2024年第3期49卷 160-165页

作者：韩原臻殷玉枫王嘉誉太原科技大学机械工程学院山西太原030024

起飞转速是空气轴承的重要性能指标。以螺旋槽空气轴承为研究对象,运用摄动法求解等温可压缩条件下螺旋槽气体润滑轴承压力分布的微分方程,得到空气轴承压力分布及承载力等特性;以最大承载力为目标,计算螺旋槽空气轴承的结构参数,并对... 详细信息

起飞转速是空气轴承的重要性能指标。以螺旋槽空气轴承为研究对象,运用摄动法求解等温可压缩条件下螺旋槽气体润滑轴承压力分布的微分方程,得到空气轴承压力分布及承载力等特性;以最大承载力为目标,计算螺旋槽空气轴承的结构参数,并对设计的空气轴承进行试验,探究其不同载荷下的起飞速度。试验结果表明:空载状态下,转速约为1 200 r/min时空气轴承的转子与轴承套脱离接触,达到起飞速度;螺旋槽空气轴承的起飞速度与起飞转矩均随着的载荷的增加而逐渐升高,随着转速的升高,轴承的承载能力也越来越大。研究表明所设计的螺旋槽空气轴承具有良好的性能,为后续螺旋槽轴承设计优化及实际应用提供了理论与实践基础。

关键词：螺旋槽空气轴承起飞速度承载力气体润滑

消退素D1治疗系统性红斑狼疮模型小鼠的分子机制

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中华医学杂志 2024年第19期104卷 1721-1727页

作者：王鸣军周玲武剑尹玉峰曹晶黄龄程韬苏州大学附属第一医院风湿免疫科苏州苏州大学附属第一医院肾内科苏州

目的探讨消退素D1（RvD1）治疗系统性红斑狼疮（SLE）模型小鼠的分子机制。方法选取8周龄雌性MRL/lpr小鼠（SLE小鼠模型, 12只）和ICR小鼠（健康对照小鼠, 6只）, 将MRL/lpr小鼠按照随机数字表法随机分为磷酸缓冲溶液（PBS）组和RvD1组... 详细信息

目的探讨消退素D1（RvD1）治疗系统性红斑狼疮（SLE）模型小鼠的分子机制。方法选取8周龄雌性MRL/lpr小鼠（SLE小鼠模型, 12只）和ICR小鼠（健康对照小鼠, 6只）, 将MRL/lpr小鼠按照随机数字表法随机分为磷酸缓冲溶液（PBS）组和RvD1组（每组各6只）, 尾静脉分别注射0.2 ml PBS和5 μg/kg RvD1, 8周后检测PBS组和RvD1组小鼠血清抗双链DNA（dsDNA）抗体、尿蛋白和滤泡辅助T细胞（Tfh）比例。处死小鼠后分离PBS组小鼠脾脏CD4+T细胞, 按随机数字表法将细胞分为CD4+T细胞+二甲基亚砜（DMSO）(A组)、CD4+T细胞+RvD1（B组）、初始CD4+T细胞+DMSO（C组）、初始CD4+T细胞+RvD1（D组）, 检测各组细胞E26转录因子1（ETS1）mRNA的表达水平和Tfh比例和分化情况。将miR-338-3p抑制剂与PBS组脾脏CD4+T细胞或初始CD4+T细胞共培养, 检测细胞ETS1 mRNA的表达水平和Tfh的分化情况。用shRNA-circ0006779慢病毒或空载慢病毒感染ICR组小鼠的脾脏CD4+T细胞, 检测各组细胞miR-338-3p mRNA、ETS1 mRNA的水平和Tfh的分化情况（细胞实验的筛孔数均为5）。结果 RvD1组小鼠脾脏CD4+T细胞ETS1 mRNA表达量高于PBS组（1.00±0.33比0.34±0.13, P=0.014）;RvD1组小鼠脾重、血清抗dsDNA抗体水平、尿蛋白水平、Tfh细胞比例均低于PBS组（均P<0.05）。RvD1与CD4+T细胞体外共培养结果发现:B组CD4+T细胞ETS1 mRNA表达量高于A组（1.00±0.08比0.25±0.05, P<0.001）、Tfh比例低于A组（16.06%±3.06%比21.76%±3.42%, P=0.020）;RvD1与初始CD4+T细胞体外共培养结果发现:D组初始CD4+T ETS1 mRNA表达量高于C组（1.00±0.25比0.21±0.16, P<0.001）、Tfh分化程度低于C组（8.81%±1.01%比12.60%±1.86%, P=0.011）。与不加miR-338-3p抑制剂相比, miR-338-3p抑制剂可以增加PBS组CD4+T细胞ETS1 mRNA表达量（1.00±0.24比0.10±0.01, P<0.001）, 降低Tfh细胞分化程度（9.56%±1.53%比13.60%±1.32%, P<0.001）;与空载慢病毒组相比, shRNA-circ0006779慢病毒可以增加ICR组CD4+T细胞miR-338-3p水平（1.00±0.22比1.38±0.21, P=0.002）, 降低ETS1 mRNA水平（0.76±0.13比1.00±0.14, P=0.005）, 提高Tfh细胞分化程度（4.00%±0.65%比1.68%±0.60%, P<0.001）。结论 RvD1通过circ0006779/miRNA-3384-3p/ETS1轴抑制Tfh细胞分化, 治疗小鼠的SLE。

关键词：红斑狼疮, 系统性消退素D1 辅助性T细胞 E26转录因子1 小RNA 338-3p 环状RNA 0006779

初诊SLE患者抗CTLA-4抗体水平及其临床意义

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安徽医学 2024年第7期45卷 816-820页

作者：尹玉峰周二叶武剑苏州大学附属第一医院风湿免疫科江苏苏州215006

目的探讨初诊系统性红斑狼疮(SLE)患者血清中抗CTLA-4抗体水平及其临床意义。方法选取2022年1月至2023年6月在苏州大学附属第一医院风湿免疫科就诊的初诊SLE患者56例作为病例组,同时选取我院体检中心52例体检者作为对照组。采用酶联免... 详细信息

目的探讨初诊系统性红斑狼疮(SLE)患者血清中抗CTLA-4抗体水平及其临床意义。方法选取2022年1月至2023年6月在苏州大学附属第一医院风湿免疫科就诊的初诊SLE患者56例作为病例组,同时选取我院体检中心52例体检者作为对照组。采用酶联免疫吸附试验(ELISA)检测两组血清中IgG和IgM型抗CTLA-4抗体。比较不同临床特征(包括皮疹、口腔溃疡、浆膜炎等等)初诊SLE患者组间抗CTLA-4抗体水平差异。采用Pearson相关分析评估初诊SLE患者抗CTLA-4抗体与疾病活动指标[包括SLE疾病活动指数2000版(SLEDAI-2K)、抗ds-DNA以及C反应蛋白(CRP)]的关系。结果病例组IgG和IgM型抗CTLA-4水平均高于对照组(t=4.657、5.014,P均<0.05);IgG和IgM型抗CTLA-4抗体水平在SLE合并浆膜炎的患者中高于未合并浆膜炎患者(t=1.849、2.013;P=0.046、0.032);Pearson相关分析显示,IgM型抗CTLA-4抗体与SLEDAI-2K(r=0.425,P=0.029)及补体C3(r=-0.494,P=0.029)呈正相关;IgG和IgM型抗CTLA-4抗体与CRP(r=0.301、0.404;P=0.041、0.022)和抗ds-DNA抗体(r=0.644、0.363;P=0.002、0.036)呈正相关。结论初诊SLE患者血清抗CTLA-4抗体呈高表达,且该抗体与浆膜炎、疾病活动度相关。

关键词：初诊系统性红斑狼疮细胞毒性T淋巴细胞相关蛋白4 浆膜炎疾病活动度

绿原酸可减轻高水平FAs诱导犊牛肝细胞线粒体功能障碍

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中国兽医学报 2024年第5期44卷 1014-1018页

作者：温佳楠尹钰锋李铭王晶晶季子崴田艳王爽徐闯杨威张冰冰黑龙江八一农垦大学生命科学技术学院黑龙江大庆163319 黑龙江八一农垦大学动物科技学院黑龙江大庆163319 中国农业大学动物医学院北京100191

旨在探讨绿原酸(cholorogenic acid, CGA)是否能通过内质网应激减轻犊牛肝细胞的线粒体自噬。从犊牛中分离出的原代肝细胞经处理后进行培养。首先通过检测犊牛肝细胞中的ROS筛选CGA的最佳质量浓度。用1.2 mmol/L FAs刺激犊牛肝细胞12 h... 详细信息

旨在探讨绿原酸(cholorogenic acid, CGA)是否能通过内质网应激减轻犊牛肝细胞的线粒体自噬。从犊牛中分离出的原代肝细胞经处理后进行培养。首先通过检测犊牛肝细胞中的ROS筛选CGA的最佳质量浓度。用1.2 mmol/L FAs刺激犊牛肝细胞12 h,并用CGA处理12 h。试验设置4个处理组(Ctrl、FAs、CGA、CGA+FAs),分别检测线粒体功能相关指标(CypD)以及线粒体自噬相关蛋白(Parkin、LC3)的表达。结果表明,FAs增加了线粒体功能相关指标(CypD)以及线粒体自噬相关蛋白(Parkin、LC3)的表达,而CGA可减轻这些影响。为进一步研究CGA对线粒体功能的影响,用内质网应激诱导剂毒胡萝卜素(thapsigargin, TG)处理犊牛肝细胞12 h。结果显示,TG中线粒体功能相关指标(CypD)以及线粒体自噬相关蛋白(Parkin、LC3)的表达均有所增加,而CGA可减轻这些影响,说明CGA可通过内质网应激下调线粒体自噬。总之,本研究结果表明,CGA是一种有效缓解犊牛肝细胞线粒体自噬的治疗工具。

关键词：泌乳营养内质网应激线粒体自噬

Improving corrosion resistance of additively manufactured WE43 magnesium alloy by high temperature oxidation for biodegradable applications

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Journal of Magnesium and Alloys 2024年第3期12卷 940-953页

作者： Jinge Liu Bangzhao yin Fei Song Bingchuan Liu Bo Peng Peng Wen Yun Tian yufeng Zheng Xiaolin Ma Caimei Wang State Key Laboratory of Tribology in Advanced Equipment Beijing100084China Department of Mechanical Engineering Tsinghua UniversityBeijing 100084China Department of Orthopaedics Beijing Tsinghua Changgung HospitalInstitute for Precision MedicineTsinghua UniversityBeijing102218China Department of Orthopaedics Peking University Third HospitalBeijing 100191China Engineering Research Center of Bone and Joint Precision Medicine Ministry of EducationBeijing 100191China School of Materials Science and Engineering Peking UniversityBeijing 100871China Beijing AKEC Medical Co. Ltd.Beijing 102200China

Laser powder bed fusion(L-PBF)has been employed to additively manufacture WE43 magnesium(Mg)alloy biodegradable implants,but WE43 L-PBF samples exhibit excessively rapid corrosion.In this work,dense WE43 L-PBF samples were built with the relativity density reaching 99.9%.High temperature oxidation was performed on the L-PBF samples in circulating air via various heating temperatures and holding durations.The oxidation and diffusion at the elevated temperature generated a gradient structure composed of an oxide layer at the surface,a transition layer in the middle and the matrix.The oxide layer consisted of rare earth(RE)oxides,and became dense and thick with increasing the holding duration.The matrix was composed ofα-Mg,RE oxides and Mg_(24)RE_(5) precipitates.The precipitates almost disappeared in the transition layer.Enhanced passivation effect was observed in the samples treated by a suitable high temperature oxidation.The original L-PBF samples lost 40%weight after 3-day immersion in Hank’s solution,and broke into fragments after 7-day immersion.The casted and solution treated samples lost roughly half of the weight after 28-day immersion.The high temperature oxidation samples,which were heated at 525℃ for 8 h,kept the structural integrity,and lost only 6.88%weight after 28-day immersion.The substantially improved corrosion resistance was contributed to the gradient structure at the surface.On one hand,the outmost dense layer of RE oxides isolated the corrosive medium;on the other hand,the transition layer considerably inhibited the corrosion owing to the lack of precipitates.Overall,high temperature oxidation provides an efficient,economic and safe approach to inhibit the corrosion of WE43 L-PBF samples,and has promising prospects for future clinical applications.

关键词： Laser powder bed fusion Biodegradable magnesium alloy High temperature oxidation Corrosion resistance WE43.

Influence of layer thickness on formation quality,microstructure,mechanical properties,and corrosion resistance of WE43 magnesium alloy fabricated by laser powder bed fusion

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Journal of Magnesium and Alloys 2024年第4期12卷 1367-1385页

作者： Bangzhao yin Jinge Liu Bo Peng Mengran Zhou Bingchuan Liu Xiaolin Ma Caimei Wang Peng Wen Yun Tian yufeng Zheng State Key Laboratory of Tribology in Advanced Equipment Beijing100084China Department of Mechanical Engineering Tsinghua UniversityBeijing 100084China Institute for Precision Medicine Tsinghua UniversityBeijing102218China Department of Orthopaedics Peking University Third HospitalBeijing 100191China Beijing AKEC Medical Co. Ltd.Beijing 102200China School of Materials Science and Engineering Peking UniversityBeijing 100871China Engineering Research Center of Bone and Joint Precision Medicine Ministry of EducationBeijing 100191China

Laser powder bed fusion(L-PBF)of Mg alloys has provided tremendous opportunities for customized production of aeronautical and medical parts.Layer thickness(LT)is of great significance to the L-PBF process but has not been studied for Mg alloys.In this study,WE43 Mg alloy bulk cubes,porous scaffolds,and thin walls with layer thicknesses of 10,20,30,and 40μm were fabricated.The required laser energy input increased with increasing layer thickness and was different for the bulk cubes and porous scaffolds.Porosity tended to occur at the connection joints in porous scaffolds for LT40 and could be eliminated by reducing the laser energy input.For thin wall parts,a large overhang angle or a small wall thickness resulted in porosity when a large layer thicknesses was used,and the porosity disappeared by reducing the layer thickness or laser energy input.A deeper keyhole penetration was found in all occasions with porosity,explaining the influence of layer thickness,geometrical structure,and laser energy input on the porosity.All the samples achieved a high fusion quality with a relative density of over 99.5%using the optimized laser energy input.The increased layer thickness resulted to more precipitation phases,finer grain sizes and decreased grain texture.With the similar high fusion quality,the tensile strength and elongation of bulk samples were significantly improved from 257 MPa and 1.41%with the 10μm layer to 287 MPa and 15.12%with the 40μm layer,in accordance with the microstructural change.The effect of layer thickness on the compressive properties of porous scaffolds was limited.However,the corrosion rate of bulk samples accelerated with increasing the layer thickness,mainly attributed to the increased number of precipitation phases.

关键词： Magnesium alloy WE43 Laser powder bed fusion Layer thickness Process optimization

Joint optimization of serving node selection and wireless resources allocation for transactions data in mobile blockchain enhanced Internet of Things

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High Technology Letters 2023年第2期29卷 181-193页

作者：尹玉峰 WU Wenjun GAO Yang JIN Kaiqi ZHANG Yanhua SUN Teng Faculty of Information Technology Beijing University of TechnologyBeijing 100124P.R.China

With the increased emphasis on data security in the Internet of Things(IoT), blockchain has received more and more attention.Due to the computing consuming characteristics of blockchain, mobile edge computing(MEC) is integrated into IoT.However, how to efficiently use edge computing resources to process the computing tasks of blockchain from IoT devices has not been fully studied.In this paper, the MEC and blockchain-enhanced IoT is considered.The transactions recording the data or other application information are generated by the IoT devices, and they are offloaded to the MEC servers to join the blockchain.The practical Byzantine fault tolerance(PBFT) consensus mechanism is used among all the MEC servers which are also the blockchain nodes, and the latency of the consensus process is modeled with the consideration of characteristics of the wireless network.The joint optimization problem of serving base station(BS) selection and wireless transmission resources allocation is modeled as a Markov decision process(MDP), and the long-term system utility is defined based on task reward, credit value, the latency of infrastructure layer and blockchain layer, and computing cost.A double deep Q learning(DQN) based transactions offloading algorithm(DDQN-TOA) is proposed, and simulation results show the advantages of the proposed algorithm in comparison to other methods.

关键词： Internet of Things(IoT) mobile edge computing(MEC) blockchain deep reinforcement learning(DRL)

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滚柱轴承离合器油膜厚度的计算

润滑与密封 2006年第10期31卷 148-150,170页

作者：殷玉枫常争艳刘中太原科技大学机电工程学院山西太原030024

利用弹性流体动力润滑理论对滚柱轴承离合器的油膜厚度进行了分析,给出了最小油膜厚度的计算公式,进行了实例计算,为滚柱轴承离合器的设计和在制造精度上对其进行严格控制,提高其疲劳寿命和可靠性提供了理论依据。

关键词：弹性流体动力润滑滚柱轴承离合器最小油膜厚度疲劳寿命制造精度